1. Field of the Invention
This invention relates to N-substituted-P-(2-chloroethyl)-phosphonamidate compounds useful as plant growth regulators and processes for their preparation.
2. Background of the Prior Art
The art is aware that certain phosphorus containing compounds are useful as plant growth regulators. One of the most important phosphorus compounds of this type is 2-chloroethyl-phosphonic acid which has found importance as a plant growth regulator, particularly, in the treatment of pineapples, soy beans and other plants to control their rate of growth. The present invention provides a new class of phosphorus-containing compounds useful as plant growth regulators not known heretofore, which compounds have utility in this area equivalent to 2-chloroethyl phosphonic acid. One of the primary characteristics of products of these types resides in the presence of the 2-chloroethyl group as this is important to the plant growth stimulating activity because it is believed that the action of the compounds is due to the fact that they are absorbed by the plant and release ethylene, a known plant regulator in a form in which it can be used by the plant.
The art is aware of various nitrogen-substituted phosphonamidates but none are suggested as having plant growth activity equivalent to those of the present invention. For example, in Chemical Abstracts, Vol. 66, page 27,927, there is disclosed ethyl N,N-diethyl-P-chloromethyl phosphonamidate, which is related to the compounds of the present invention, but the presence of the chloromethyl group negates its value in the plant growth area as the compound cannot release ethylene. In addition, in U.S. Pat. No. 3,010,986, there is disclosed the cyclohexyl ester of N,N-diallyl-P-(2-chloroethyl)-phosphonamidate, prepared by the reaction of 2-chloroethyl phosphonyl dichloride and cyclohexanol followed by the reaction of this intermediate with diallyl amine which compound is obviously different than those claimed herein. Also, in Chemical Abstracts, Vol. 42, page 7,243, the compound 2-chloroethyl-N-phenyl-P-(2-chloroethyl) phosphonamidate is suggested as being prepared from its acid chloride and aniline. In none of these prior art teachings however, is there a disclosure of the 2-chloroethyl-N-substituted phosphorus compounds of this invention and in particular, 2-chloroethyl-N-substituted phosphorus compounds which have unique activity as plant growth regulators. Accordingly, there is a clear need in the art for products of this type and processes by which they may be prepared.